The present invention relates to ultrasonic inspection of workpieces and, more particularly, to a fixture assembly for holding multiple ultrasonic transducers to provide substantially complete ultrasonic inspection of a portion of a workpiece in a single scanning operation or in a minimum number of scans to improve throughput and inspection efficiency.
Typically, an ultrasonic inspection will involve a single transducer mounted to an ultrasonic inspection system manipulator. This single transducer, however, will inject or introduce ultrasonic energy or sound waves into a workpiece under inspection only in one direction and also receive a return or reflected signal or sound waves from a flaw or defect along this same direction. For example, a longitudinal ultrasonic wave is typically introduced into the workpiece along a path normal to the workpiece surface by a transducer and the transducer will receive return ultrasonic energy along this same normal path. Therefore, flaws or defects which are oriented substantially parallel to the workpiece surface will be easily detected; however, flaws or defects which are not oriented substantially parallel to the workpiece surface, such as flaws oriented diagonally or substantially vertical relative to the workpiece surface, may be missed or deemed insignificant because the defect or flaw is only inspected from one direction and may appear small and insignificant in this direction.
Ultrasonic inspection from one direction or perspective, normal to the workpiece surface, may be adequate for some workpieces; however, for those components requiring a more complete and thorough inspection, it may be desirable to introduce or inject a shearwave ultrasonic signal into the workpiece at a predetermined angle of incidence to provide a desired angle of refraction of the ultrasonic energy upon entering the workpiece. As many as three or more separate ultrasonic scans may then be required to substantially completely inspect a workpiece. A longitudinal ultrasonic inspection scan is performed to pick up those flaws or defects oriented substantially parallel to the workpiece surface and at least two circumferential shearwave ultrasonic inspection scans may be required to pick up those flaws or defects which may be oriented substantially vertical or at some angle relative to the surface of the workpiece.
Phased array transducers are available for performing longitudinal and shearwave inspections in a single scan; however, these phased array transducers are more expensive than a single conventional transducer and if a single element of the array fails or goes bad, the entire phased array must be replaced rather than replacing a single transducer.
It is accordingly a primary object of the present invention to provide a novel fixture assembly for holding multiple ultrasonic transducers to provide substantially complete ultrasonic inspection of a workpiece in a single scanning operation or in a minimum number of required scanning operations.
It is another object of the present invention to provide a novel ultrasonic fixture assembly for holding multiple conventional ultrasonic transducers such that if one transducer fails or goes bad, only that single bad transducer need be replaced.
It is a further object of the present invention to provide a novel ultrasonic fixture assembly for holding multiple conventional ultrasonic transducers which is usable with conventionally known immersion type ultrasonic inspection systems and can be easily attached or detached from the manipulators of such systems.
These and other objects of the present invention, together with the features and advantages thereof, will become apparent from the following specification when read with the accompanying drawings.